Fracture repair is the process of rejoining and realigning broken bones. Fracture repair is required when there is a need for restoration of the normal position and function of the broken bone. Throughout the stages of fracture healing, the bones must be held firmly in the correct position and supported until it is strong enough to bear weight. In the event the fracture is not properly repaired, malalignment of the bone may occur, resulting in possible physical dysfunction of the bone or joint of that region of the body.
The addition of bone cements or other compounds to a fractured bone for repairing bone and, for example, joining bones are known in the art and typically requires at least two steps. Conventional bone cement injection devices are similar to a household caulking gun. Typically, the injection device has a pistol-shaped body, which supports a cartridge containing the bone cement. Bone cements are usually found as two component systems (powder and liquid) and must be mixed in a mixer and transferred into the cartridge for injection. In conventional bone cement mixers, the mixing element or stirrer is inserted into the mixing vessel after the bone cement powder and monomer liquid have been placed in the vessel. When mixing is complete, the stirrer is withdrawn from the cement and the cement is manually transferred from the mixing vessel to the injection device. Stirrer withdrawal from the cement exposes a large surface area of the cement to room air and undesirably introduces significant amounts of monomer liquid vapor in the ambient air. This process is unpleasant for individuals mixing the cement, since the mixed cement often contains an offensive, noxious odor. Furthermore, removal of the mixed cement from the mixing vessel into the cartridge of the injection device is cumbersome, time consuming, and has the potential for being mishandled and/or dropped.
Once the bone cement has been added to the cartridge of the injection device, the bone cement is delivered to the site of the bone fracture. Because the bone cement may be quite thick and viscous, delivering the bone cement from the injection device often requires a great deal of effort applied to the device plunger. Thus, both strength and dexterity are required on the part of the medical professional performing the procedure. The bone cement itself may cause complications including the leakage of the bone cement to an area outside of the fractured bone site, which can result in soft tissue damage as well as nerve root pain and compression. Other reported complications include pulmonary embolism, respiratory and cardiac failure, and death.
Thus, there is a need in the art for devices that can be used to repair a weakened or fractured bone in an effective, efficient and safe manner.